Insole for footwear

ABSTRACT

The present invention aims at controlling the balance of a skeletal structure of a foot of a user, and reducing the stress applied on the feet or body of the user wearing the footwear. In order to realize the above objects, the present invention provides an insole  1  for a footwear, having an elevated convexed center section  2  formed on a contact surface to be in contact with a foot, positioned at an intermediate area between a portion corresponding to a base of a big toe of the foot and a portion corresponding to a base of a little toe of the foot, and a concaved center section  3  formed on the contact surface in contact with the foot, positioned on both sides of the convexed section  2 , and extending from the portion corresponding to the base of the big toe or the portion corresponding to the base of the little toe to the portion corresponding to a heel.

The present application is based on and claims priority of Japanese Patent Application No. 2013-228515 filed on Nov. 1, 2013, the entire contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an insole for a footwear.

2. Description of the Related Art

Generally, heavy load is applied on a footwear by the weight of a user during use, so in order to enhance the shock absorbing properties provided by the footwear when the user wearing the footwear is walking or running, or to improve the fitting properties thereof, various insoles for footwear have been devised, as taught in Patent Literature 1 (Japanese Patent Application Laid-Open Publication No. 2001-269201), Patent Literature 2 (Japanese Patent Application Laid-Open Publication No. 2005-205204), Patent Literature 3 (Japanese Patent Application Laid-Open Publication No. 2007-202959) and Patent Literature 4 (Japanese Patent Application Laid-Open Publication No. 2011-110397).

As described in the above documents, heavy load is applied on the footwear, but at the same time, heavy load is also applied on foot joints and the like, so that in some cases, the user may feel pain or experience distortion of the foot or the body.

Therefore, when the user is walking or running, or when the user is exercising, skiing, or playing tennis, golf, or soccer and the like, it becomes necessary to provide a means for adjusting the balance of the skeletal structure of the foot of the user wearing the footwear, so as to prevent any stress from being applied on the feet or the body.

SUMMARY OF THE INVENTION

The present invention aims at solving the problems of the prior art by providing an insole for a footwear comprising an elevated convexed section formed on a contact surface to be in contact with a foot placed on the insole, positioned at an intermediate area between a portion corresponding to a base of a big toe of the foot and a portion corresponding to a base of a little toe of the foot; and a concaved section formed on the contact surface in contact with the foot, positioned on both sides of the convexed section, and extending from the portion corresponding to the base of the big toe or the portion corresponding to the base of the little toe to the portion corresponding to a heel, according to which the skeletal structure of the foot can be positioned at a preferable position when the user wears the footwear.

Further, the insole can further comprise a linear convexed section formed on a bottom surface of the insole for footwear coming in contact with an inner sole of the footwear, formed along a curved line connecting the base portions of the respective toes of the foot from the portion corresponding to the base of the big toe to the portion corresponding to the base of the little toe.

Moreover, the present insole of a footwear comprises a hard support means disposed on a bottom surface of the insole for footwear coming in contact with an inner sole of the footwear and designed to cover the portion corresponding to base portions of respective toes of the foot to the portion corresponding to the heel, wherein the support means comprises a first void section disposed between the portion corresponding to the base of the big toe and the portion corresponding to the heel, which is filled integrally with the insole using the material constituting the insole, and a second void section having a smaller area than the first void section and disposed between the portion corresponding to the base of the little toe and the portion corresponding to the heel, which is filled integrally with the insole using the material constituting the insole, based on which the strength of both side surfaces can be enhanced while ensuring the flexibility of both sides of the foot wearing the present insole.

For example, the first void section is composed of multiple holes, and the second void section is composed of a smaller number of holes than the multiple holes.

According to the present invention, by wearing the footwear having the insole laid on the inner sole according to the present invention, the skeletal structure of the foot can be arranged at a preferable position, and the stress applied on the foot and the body when the user is walking, running, exercising and the like can be reduced even further.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view illustrating the structure of a surface of an insole for a footwear 1 (coming in contact with the foot) according to a preferred embodiment of the present invention;

FIG. 2 is across-sectional view illustrating the structure of the insole for a footwear 1 cut at line A-A of FIG. 1;

FIG. 3 is a plan view illustrating the structure of a bottom surface (coming in contact with an inner sole of the footwear) of the insole for a footwear 1 illustrated in FIG. 1;

FIG. 4 is a side view showing the structure of the insole for a footwear 1 illustrated in FIG. 1 seen from the side of a side surface 1 a; and

FIG. 5 is a view illustrating a human foot and a skeletal structure thereof illustrating the function of the insole for a footwear 1 illustrated in FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Now, the preferred embodiments of an insole for footwear according to the present invention will be described with reference to the drawings. The same reference numbers in the drawings refer to the same or equivalent portions.

FIG. 1 is a plan view illustrating the configuration of a surface (surface in contact with foot; used in the same meaning hereafter) of an insole for footwear 1 according to a preferred embodiment of the present invention. As shown in FIG. 1, the insole for footwear 1 is formed into a shape of a human foot and used by placing on an innersole of a footwear, wherein the surface of the insole on which a foot of a user wearing the footwear comes into contact with has a center convexed section 2, a center concaved section 3, a heel concaved section 4 and a perforated section 5.

The insole for footwear 1 is molded using rubber or synthetic resin, for example, and preferably molded using soft synthetic resin, such as ethylene-vinyl acetate copolymer (EVA). The EVA material is a light-weight, flexible material capable of absorbing shock, also having superior water resistance, heat resistance and water repellency, which can be used from minus 70 degrees to 70 degrees Celsius environment and maintains elasticity and stability even in low temperatures.

The center convexed section 2 is a gently elevated section, which is positioned at an intermediate section between a portion corresponding to the base of the big toe of a foot and a portion corresponding to the base of the little toe of a foot on the contact surface of the foot, and formed at the center section of the insole for footwear 1.

Further, the center concaved section 3 is formed in a concaved shape along the sides of the center convexed section 2 on the contact surface. That is, the center concaved section 3 is formed on the sides of the center convexed section 2 of the insole for footwear 1, extending from the portion corresponding to the base of the big toe or the portion corresponding to the base of the little toe toward the portion corresponding to the heel.

The heel concaved section 4 is a concaved section formed on the area of the contact surface where the heel of a foot is positioned when the user wears the footwear. The heel concaved section 4 has a function to firmly enwrap the heel and gather the fat layer of the heel expanded by weight, so as to buffer the shock applied on the body from the ground.

The perforated section 5 has multiple perforated holes formed throughout an area from the portion corresponding to the base of the big toe to the portion corresponding to the end of the toe on the insole 1, for ensuring ventilation between the footwear and the insole for footwear 1. The perforated section 5 is provided to the area excluding the areas corresponding to the big toe, the base of the big toe and the base of the little toe of the foot. The reason why these areas corresponding to the big toe, the base of the big toe and the base of the little toe of the foot are excluded is because these areas receive the greatest force applied to the foot during walking and kicking action, so that these areas are not perforated to prevent the user from feeling discomfort in these areas and to prevent dispersion of the force in which the foot kicks the ground.

FIG. 2 is a cross-sectional view showing the configuration in which the insole for footwear 1 is cut along line A-A illustrated in FIG. 1. As shown in FIG. 2, both side surfaces 1 a and 1 b are designed so as to enwrap the foot, wherein a side surface 1 a positioned on a big-toe side of the foot (hereinafter also referred to as the “inner side”) is formed higher than a side surface 1 b positioned on a little-toe side of the foot (hereinafter also referred to as the “outer side”).

Further, the center concaved section 3 is formed in a concaved shape along the side surfaces 1 a and 1 b formed on the inner and outer sides of the surface of the insole for footwear 1, and the center convexed section 2 is formed in a convexed shape at the center section of the surface of the insole and sandwiched by both center concaved sections 3.

The illustrated configuration enables to maintain a preferable arrangement of skeletal structure in the foot breadth direction illustrated by curved line AR1 of FIG. 5, and further, the center concaved section 3 enables to facilitate the movement of the tendon extending from the base of the big toe and the base of the little toe to the heel section. Further, the side surfaces 1 a and 1 b support the inner side and the outer side of the foot firmly from the sides, so that during the action for moving the foot frontward, this structure enables to stabilize the skeletal structure of the foot and reduce energy loss that may occur between the footwear.

Further, a hard cup 10 is attached to a bottom surface of the insole for footwear 1 coming into contact with the inner sole of the footwear (hereafter simply referred to as the bottom surface). The hard cup 10 is molded, for example, using hard resin such as thermoplastic polyurethane (TPU) (for example, the degree of hardness of the resin is approximately 85).

If the insole for footwear 1 is formed of an EVA material, the hard cup 10 molded from TPU material is pressure-bonded to the insole for footwear 1 by a pressure of 130 to 150 tons.

FIG. 3 is a plan view illustrating the structure of a bottom surface of the insole for footwear 1 illustrated in FIG. 1. As shown in FIG. 3, on the bottom surface of the insole for footwear 1, a linear convexed section 8 is formed integrally to a portion of the insole for footwear 1 so as to be projected along a curved line connecting the portions corresponding to bases of the respective toes of the foot from the portion corresponding to the base of the big toe to the portion corresponding to the base of the little toe when the user wears the footwear.

FIG. 3 illustrates one example of the linear convexed section 8 composed of three lines that are cut at the center section, but this is merely an example, and the linear convexed section 8 can be composed of any number of lines cut at any section, and the interval between the lines can be varied, or there may be no cut section.

By cutting the insole 1 along the linear convexed section 8 formed on the bottom surface of the insole for footwear 1, the insole 1 can be formed without a toe section in the longitudinal direction. Thereby, the insole can be applied to a footwear with a narrowed toe end, for example.

Further, on the bottom surface of the insole for footwear 1 is attached a hard cup 10 as mentioned earlier, so as to cover the area from the portion corresponding to the base of the toes of the foot to the portion corresponding to the heel.

Now, as shown in FIG. 3, the hard cup 10 is formed so that the length is longer at the inner side (the side close to the side surface 1 a) than at the outer side (the side close to the side surface 1 b) of the foot.

Further, the hard cup 10 has formed thereto a first void section disposed to the area between the portion corresponding to the base of the big toe and the portion corresponding to the heel of the foot and integrally filled with the insole for footwear 1 using the material constituting the insole for footwear 1, and a second void section whose area is smaller than the first void section, disposed to the area between the portion corresponding to the base of the little toe and the portion corresponding to the heel of the foot and integrally filled with the insole for footwear 1 using the same material.

According to this configuration, the insole enables to enhance the force supporting both side surfaces of the foot and provides flexibility to the inner side surface and the outer side surface of the foot. Moreover, the hard cup 10 enables the reduce the stress applied on the foot from the side surfaces while maintaining the support provided to the bottom of the foot, so that the hard cup 10 supports the skeletal structure of the foot and maintains the smooth movement of the foot.

Now, the shape of the first and second void sections can be holes or slits. For example, if the void sections are formed of holes having a fixed shape and size, the first void section can be formed of multiple holes and the second void section can be formed of a number of holes smaller than the number of the holes forming the first void section. FIG. 3 illustrates one example where the first void section is formed of four shock diffusing holes 6, and the second void section is formed of three shock diffusing holes 6.

The hard cup 10 also includes a heel hole section 7 formed at the heel section of the foot, which is formed integrally with the insole for footwear 1 and filled with the material constituting the insole for footwear 1.

Since the hard cup 10 has the above-described shock diffusing holes 6 and the heel hole section 7 formed thereto, the hard cup 10 will have flexibility, so that the shock received when the foot is landed on the ground can be appropriately dispersed, and at the same time, the stability of the bottom of the foot can be maintained.

Further, the hard cup 10 has a balancer 11 arranged to extend from the portion corresponding to the base of the big toe or the little toe toward the portion corresponding to the heel and being adjacent to the center side of the first or second void section, which is formed of the material constituting the hard cup 10 and projected integrally with the hard cup 10 toward the side coming in contact with the footwear.

The balancer 11 enables to enhance the strength of the hard cup 10 while realizing moderate elasticity, and by having the hard cup 10 exert a function similar to a spring when it is deformed by the shock of landing of the foot or the like, a force is created to help the foot kick the ground.

FIG. 4 is a side view showing the structure when the insole for footwear 1 illustrated in FIG. 1 is seen from the side. As shown in FIG. 4, the linear convexed section 8 is formed on the bottom surface of the insole for footwear 1, which can be cut lines formed integrally to the insole in the breadth direction of the foot, as mentioned earlier.

The hard cup 10 attached to the bottom surface of the insole is formed so that a portion 12 corresponding to the arch of the foot is warped upward, and the balancer 11 having a convexed shape as mentioned earlier is provided on the arch portion 12.

As described, since the portion corresponding to the arch is warped upward to fit the shape of the bottom of the foot so that there is no clearance between the footwear and the foot, the user's foot will not easily move in the footwear and will be stabilized, so that comfortable walking or running movements can be supported.

According to the insole for footwear 1 of the present embodiment, a gently elevated center convexed section 2 is formed between the portion corresponding to the base of the big toe and the portion corresponding to the base of the little toe of the foot on the surface in contact with the foot, so that the skeletal structure of the foot in the foot breadth direction shown by curved line AR1 of FIG. 5 can be arranged at a preferable position, and the clearance of bones of the foot can also be well balanced in the direction along a curved line AR2 on the big-toe side and a curved line AR3 on the little-toe side, so that as a result, it becomes possible to preferably control (assemble) the skeletal structure of the whole foot of the user wearing the footwear.

Thereby, the operation of the muscles of the foot of the user wearing the footwear can be normalized, and the primary functions of the foot including stability, shock absorbing property and kicking force can be exerted. As a result, the control performance of the movement of the foot in the front and back directions and the left and right directions can be enhanced, and the load applied on the foot can be reduced even further.

Moreover, the center concaved section 3 formed on both sides of the center convexed section 2 on the surface in contact with the foot is designed to extend from the portion corresponding to the base of the big toe or from the portion corresponding to the base of the little toe to the portion corresponding to the heel, helping the smooth movement of the tendon on the bottom of the foot extending from the base of the big toe and the base of the little toe toward the heel of the foot, and enabling to reduce the load applied on the foot even further.

When the present insole 1 is to be applied to a footwear designed to have a narrowed end or a small-sized footwear and the whole insole 1 cannot be inserted thereto, the insole can be cut from the linear convexed section 8 formed on the bottom surface of the insole 1 to be inserted to such footwear. The insole having the toe end area cut can support the area from the bases of the respective toes to the heel section, so that a satisfactory effect of reducing the load applied on the foot can be realized.

By forming void sections on the outer side and the inner side of the foot in the hard cup 10 as mentioned earlier, it becomes possible to ensure the flexibility of both sides of the foot to reduce the stress applied on the foot, and enables the force of the hard cup 10 supporting the bottom side of the foot to be maintained, so that the above-described effects and effects described hereafter can be achieved by the hard cup 10 while improving the fitting of the insole for footwear 1.

As described above, since the hard cup 10 is molded using thermoplastic polyurethane (TPU) and the like having greater strength compared to the material of the insole for footwear 1, the projection on the human foot at a back section of a fifth metatarsal bone B1 illustrated in FIG. 5 is supported by a plane instead of via a point, so that the load applied to the projection is dispersed, and not only the skeletal structure of the foot along curved line AR2 at the inner side of the foot but also the skeletal structure along curved line AR3 at the outer side of the foot can be flexibly and steadily supported. Thereby, smooth movement of body axis of the human body in the side direction can be realized.

Further, the hard cup 10 supports the projection on the foot on a calcaneal bone B2 illustrated in FIG. 5 by the heel hole section 7 and the like, suppressing the wiggling of the heel and enabling to control (adjust) the skeletal structure of the foot suitably along curved lines AR1, AR2 and AR3, so that the foot of the user wearing the footwear can be stabilized, and the wobbling of the foot that may occur during landing of the foot can be prevented. 

What is claimed is:
 1. An insole for a footwear comprising: an elevated convexed section formed on a contact surface to be in contact with a foot, positioned at an intermediate area between a portion corresponding to a base of a big toe of the foot and a portion corresponding to a base of a little toe of the foot; and a concaved section formed on the contact surface in contact with the foot, positioned on both sides of the convexed section, and extending from the portion corresponding to the base of the big toe or the portion corresponding to the base of the little toe to the portion corresponding to a heel.
 2. The insole for a footwear according to claim 1, wherein the insole further comprises a linear convexed section formed on a bottom surface of the insole for footwear coming in contact with an inner sole of the footwear, formed along a curved line connecting base portions of the respective toes of the foot from the portion corresponding to the base of the big toe to the portion corresponding to the base of the little toe.
 3. The insole for a footwear according to claim 1, wherein the insole further comprises a hard support means disposed on a bottom surface of the insole for footwear coming in contact with an inner sole of the footwear and designed to cover the portion corresponding to base portions of respective toes of the foot to the portion corresponding to the heel; wherein the support means comprises: a first void section disposed between the portion corresponding to the base of the big toe and the portion corresponding to the heel, which is filled integrally with the insole using the material constituting the insole; and a second void section having a smaller area than the first void section and disposed between the portion corresponding to the base of the little toe and the portion corresponding to the heel, which is filled integrally with the insole using the material constituting the insole.
 4. The insole for a footwear according to claim 3, wherein the first void section is composed of multiple holes; and the second void section is composed of a smaller number of holes than said multiple holes. 